Dilatancy in semi-solid steels at high solid fraction
Dilatancy in semi-solid steels at high solid fraction
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DOI：
10.1016/j.actamat.2016.11.066
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发表时间：
2017-02
期刊：
影响因子：
9.4
通讯作者：
K. Kareh;C. O’Sullivan;T. Nagira;H. Yasuda;C. Gourlay
中科院分区：
文献类型：
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作者：
K. Kareh;C. O’Sullivan;T. Nagira;H. Yasuda;C. Gourlay
钢中糊状区变形的研究对于限制连铸中缺陷的形成具有重要意义。在这里，我们使用原位同步辐射照相术来量化固相分数 >0.9 的等轴碳钢的剪切变形机制，并了解这些机制如何导致铸造缺陷。我们表明，晶粒组装会经历剪切引起的膨胀（雷诺膨胀），从而在高固体分数下打开充满液体的裂缝和裂缝。我们进一步展示了晶粒重排、晶粒变形和局部粗化之间的复杂相互作用，其中重排减少了晶粒与晶粒的接触面积和配位数，从而改变了应力网络，并且随着晶粒分开而驱动了粗化。
The study of mushy-zone deformation in steels is important for limiting defect formation in continuous casting. Here, we usein situsynchrotron radiography to quantify the shear deformation mechanisms of an equiaxed carbon steel at a solid fraction >0.9 and to understand how these mechanisms lead to casting defects. We show that the grain assembly undergoes shear-induced dilation (Reynolds' dilatancy) which opens liquid-filled fissures and cracks at high solid fraction. We further show a complex interaction between grain rearrangement, grain deformation and local coarsening, where rearrangement reduces the grain-grain contact area and coordination number which alters the stress network and also drives coarsening as grains move apart.